The present study is an investigation of the effects of breath management instruction on the performance of elementary brass players. The experimental group ( N = 32) received instruction on the use of air during brass performance. The control group ( N = 29) continued with instruction from their method books. Three measures for breathing (thoracic displacement, abdominal displacement, and lung capacity) and for performance (range, duration, and tone quality) were the dependent variables. The data were analyzed using multivariate and univariate analyses of covariance. Independent variables included group (experimental and control), instrument (trumpet, horn, and trombone), and grade level (fourth, fifth, and sixth). Main effects for group showed that the experimental group had significantly higher scores on measures of abdominal displacement, range, and duration ( p < .05). There were no treatment-by-instrument or treatment-by-grade-level interactions. Breathing instruction in group lessons was effective in improving the breathing and performance of elementary brass players.